How do acidic foods and drinks damage teeth?
First some background science. The pH scale measures how caustic chemicals are. Measured between the numbers 0 and 14, chemicals rating lower numbers are more strongly acidic; higher numbers reflect the opposite of acid, known as base, or alkaline. Chemicals in the middle, grading at number 7, are neutral, neither acid or alkaline. (Water is close to pH 7.) The scale is logarithmic: each number further away from 7 is 10 times stronger than the number closer to 7. Here's where it applies to teeth. The outer layer of teeth, known as enamel, starts to dissolve away at an acidic pH of 5.5 or lower. The pH of a typical soft drink is about 3.5, or 100 times more acidic than necessary to start to dissolve enamel. Coffee (fortunately) and tea are not highly acidic; sports and energy drinks and (sadly) white wine are. Foods known to be good for you, like some fruits, can be just as acidic as processed foods. Likely the strongest acid teeth encounter is not something eaten, but comes from the other direction - stomach acid. At pH 1, people with acid reflux may have extensive acid erosion of the teeth. Teeth worn by acid often look analogous to an ice cube that has had hot water poured on it.